Systematics of the Laurencia complex (Rhodomelaceae, Rhodophyta) in southern Africa

• Main Author: Francis, Caitlynne Melanie
• Other Authors: Bolton, John J
• Format: Doctoral Thesis
• Language: English
• Published: University of Cape Town 2015
• Subjects: Botany
• Online Access: http://hdl.handle.net/11427/12922

Includes bibliographical references. === The diversity, systematics and distribution of the red algal Laurencia complex (Rhodomelaceae, Rhodophyta) of South Africa were investigated, being generally poorly understood and taxonomically understudied. Prior to this study, ten currently recognised species in the Laurencia complex were recorded from South Africa: all were ascribed to the genus Laurencia J.V. Lamouroux (Laurencia sensu stricto). However, the diversity anddistribution of the complex in South Africa, and the larger South Western Indian Ocean (SWIO), have not yet been reassessed following the numerous taxonomic changes in this group published over the last two decades. The taxonomy, phylogeny and biogeography of the Laurencia complex in South Africa and apart of the SWIO were reassessed by examining external morphology, vegetative anatomy(including corps en cerise counts) and analysing the plastid-encoded rbcL gene sequence data of recent collections. The collection encompassed more than 250 specimens, were primarily from the coastline of South Africa and to a lesser extent from Madagascar, Mozambique, Reunion, Mauritius and the Europa and Glorioso Islands in the SWIO. In addition, a few new collections were included from Western Australia and Japan. The genetic analyses were done under Bayesian inference using the GTR + I + G model, from which phylogenetic hypotheses were deduced and pairwise sequence divergences were calculated.